References of "Journal of Materials Chemistry"
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See detailMagnetic Properties of Fe2GeMo3N; an Experimental and Computational Study
Battle, Peter; Sviridov, L.A.; Woolley, R. J. et al

in Journal of Materials Chemistry (2012), 22

A polycrystalline sample of Fe2GeMo3N has been synthesized by the reductive nitridation of a mixture of binary oxides in a flow of 10% dihydrogen in dinitrogen. The reaction product has been studied by ... [more ▼]

A polycrystalline sample of Fe2GeMo3N has been synthesized by the reductive nitridation of a mixture of binary oxides in a flow of 10% dihydrogen in dinitrogen. The reaction product has been studied by magnetometry, neutron diffraction and M€ossbauer spectroscopy over the temperature range 1.8 # T/K # 700. The electronic properties have been modelled by DFT and Monte Carlo methods. Fe2GeMo3N adopts the cubic h-carbide structure with a ¼ 11.1630(1) at 300 K. The electrical conductivity was found to be 0.9 mU cm over the temperature range 80 # T/K # 300. On cooling below 455 K the compound undergoes a transition to an antiferromagnetic state. The magnetic unit cell contains an antiferromagnetic arrangement of eight ferromagnetic Fe4 tetrahedra; the ordered atomic magnetic moments, 1.90(4) mB per Fe atom at 1.8 K, align along a <111> direction. DFT predicts an ordered moment of 1.831 mB per Fe, albeit with a N eel temperature of >549 K. Monte Carlo calculations confirm that the experimentally determined magnetic structure is the lowest-energy antiferromagnetic structure. These results emphasise the potential of these computational methods in the search for new magnetic materials. [less ▲]

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See detailNanosphere Lithography and Hydrothermal Growth : How to Increase Surface Area and Control Reversible Wetting Properties of ZnO Nanowire Arrays ?
Colson, Pierre ULg; Schrijnemakers, Audrey ULg; Vertruyen, Bénédicte ULg et al

in Journal of Materials Chemistry (2012), 22(33), 17086-17093

Due to their large surface-area-to-volume ratio as well as their interesting intrinsic optical and electronic properties, ZnO 1D nanostructures are part of the few dominant materials for nanotechnology ... [more ▼]

Due to their large surface-area-to-volume ratio as well as their interesting intrinsic optical and electronic properties, ZnO 1D nanostructures are part of the few dominant materials for nanotechnology. In this article, we compare two different routes of using the nanosphere lithography for the manufacturing of well-aligned, density-controlled ZnO nanowires by low-temperature hydrothermal growth. The first route uses the colloidal mask as a template for the patterned growth of the nanowires, while in the second route, the nanospheres act as a mask to pattern the seed layer. SEM and XRD characterizations are performed on samples manufactured by both routes and evidence patterned well-aligned nanowires with high c-axis texturing in the first synthetic route. Oriented growth is less pronounced in the second route, as well as the ability to adsorb dye. However, for the first route the dye loading measurements reveal that the amount of N-719 adsorbed is higher than on unpatterned ZnO nanowires films, highlighting an increased interface area. Reversible hydrophobicity to superhydrophilicity transition was observed and intelligently controlled by alternation of UV illumination and dark storage. This promising synthetic route opens exciting perspectives for the production of ZnO nanowire arrays with tunable density, wetting properties and enhanced adsorption properties. [less ▲]

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See detailDesign and synthesis of novel DOTA(Gd3+)–polymer conjugates as potential MRI contrast agents
Grogna, Mathurin ULg; Cloots, Rudi ULg; Luxen, André ULg et al

in Journal of Materials Chemistry (2011), 21(34), 12917-12926

Conventional low molecular weight gadolinium based Magnetic Resonance Imaging (MRI) contrast agents such as Magnevist® are very useful for imaging tissues. However, at the high magnetic fields used in ... [more ▼]

Conventional low molecular weight gadolinium based Magnetic Resonance Imaging (MRI) contrast agents such as Magnevist® are very useful for imaging tissues. However, at the high magnetic fields used in modern MRI equipments, their relaxivity (contrasting efficiency) is rather poor. The grafting of the gadolinium complex onto macromolecules is a way to enhance their relaxivity provided that the rotational motion of the complex is decreased significantly. Here we report the design of novel Gd3+ based MRI contrast agents with improved relaxivity and potential long blood circulation life-time. We investigate the grafting of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid, 1,4,7-tris(1,1-dimethylethyl) ester (DO3AtBu-NH2; a precursor of Gd3+ ligand) onto well-defined functional copolymers bearing activated esters (succinimidyl esters) and poly(ethylene oxide) (PEO) chains required for stealthiness. The tert-butyl groups of grafted DO3AtBu-NH2 are then deprotected by trifluoroacetic acid followed by complexation of Gd3+. Addition of free DOTA at the end of the reaction is necessary to leave the pure and stable water soluble macrocontrast agent. Importantly it shows a relaxivity at high frequencies that is 300% higher than that of the ungrafted gadolinium complex. These novel functional copolymers are therefore promising candidates as macromolecular contrast agents for MRI applications. [less ▲]

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See detailGenetically engineered polypeptides as a new tool for inorganic nano-particles separation in water based media
Vreuls, Christelle ULg; Genin, Alexis ULg; Zocchi, Germaine ULg et al

in Journal of Materials Chemistry (2011), 21

The present paper relates a method for the separation of an insoluble inorganic powder out of a mixture of several insoluble powders with different chemical compositions, using genetically engineered ... [more ▼]

The present paper relates a method for the separation of an insoluble inorganic powder out of a mixture of several insoluble powders with different chemical compositions, using genetically engineered inorganic binding peptides (GEPI). GEPI are small peptides that recognize and specifically bind an inorganic solid material. This GEPI is anchored to magnetic beads for easy recovery of the powder of interest from the mixture. [less ▲]

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See detailSustainable and bio-inspired chemistry for robust antibacterial activity of stainless steel
Faure, Emilie ULg; Lecomte, Philippe ULg; Lenoir, Sandrine et al

in Journal of Materials Chemistry (2011), 21(22), 7901-7904

We report on the original synthesis of a poly(methacrylamide) bearing (oxidized) 3,4-dihydroxyphenylalanine specially designed to (i) insure film growth by covalent coupling, (ii) covalently bind an ... [more ▼]

We report on the original synthesis of a poly(methacrylamide) bearing (oxidized) 3,4-dihydroxyphenylalanine specially designed to (i) insure film growth by covalent coupling, (ii) covalently bind an antibacterial peptide and (iii) contribute to the film cross-linking that is essential for the durability of the properties. [less ▲]

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See detailTiO2 multilayer thick films (up to 4 μm) with ordered mesoporosity: Influence of template on the film mesostructure and use as high efficiency photoelectrode in DSSCs
Dewalque, Jennifer ULg; Cloots, Rudi ULg; Mathis, François ULg et al

in Journal of Materials Chemistry (2011), 21(20), 7356-7363

Mesoporous templated anatase thin films are very promising materials to act as photoelectrode in dye-sensitized solar cell. Templated-assisted dip-coating techniques are used to obtain thin films with ... [more ▼]

Mesoporous templated anatase thin films are very promising materials to act as photoelectrode in dye-sensitized solar cell. Templated-assisted dip-coating techniques are used to obtain thin films with ordered porosity. However, monolayer films are very thin and suffer from a low quantity of active material, leading to poor photovoltaic performances. In this paper, a dip-coating-based multilayer deposition technique is reported. First, we have studied the influence of the template on the film organization and porosity in terms of long-range order, percentage of porosity, pore size and pores connectivity. Different techniques such as transmission electron microscopy (TEM), atmospheric poroellipsometry (AEP) and UV-visible absorption spectroscopy (UV-vis.) have been used to describe the microstructural features of the films with a thickness of 1 µm. The film exhibiting the highest dye loading was selected and its thickness gradually increased up to 4 µm. Finally, the photovoltaic performances of the thick films (1 to 4 µm) have been evaluated in combination with the N-719 dye and show excellent efficiency (6.1%) when compared to values reported in the literature. Such mesostructured films are compared in terms of photovoltaic performance with TiO2 nanoparticles films, generally used in DSSC. [less ▲]

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See detailSupramolecular design of high-performance poly(L-lactide)/carbon nanotube nanocomposites: from melt-processing to rheological, morphological and electrical properties
Manfredi, Erica; Meyer, Franck; Verge, Pierre et al

in Journal of Materials Chemistry (2011), 21(40), 16190-16196

The ability of omega-imidazolium functionalized poly(L-lactide) (ImPLLA) chains to improve the CNT dispersion within the PLLA matrix was demonstrated in bulk and at elevated temperatures using melt ... [more ▼]

The ability of omega-imidazolium functionalized poly(L-lactide) (ImPLLA) chains to improve the CNT dispersion within the PLLA matrix was demonstrated in bulk and at elevated temperatures using melt-processing techniques. This approach brings new supramolecular tools to the formation of CNT-based biomaterials derived from renewable resources with outstanding properties for semi-industrial applications. In this work, the PLLA/CNT nanocomposites were prepared using extrusion technology, starting from masterbatches. The rheological, morphological, electrical properties as well as Raman analyses confirmed the establishment of supramolecular cation-pi interactions between ImPLLA and CNT in the melt, leading to a fine dispersion of CNT within PLLA matrix. [less ▲]

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See detailMesoporous SiO2 thin films containing ZnO photoluminescent nanoparticles. Simultaneous SAXS / WAXS / Ellipsometry investigations
Krins, Natacha ULg; Bass, J. D.; Julián-López, B. et al

in Journal of Materials Chemistry (2011), 21

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See detailNovel photosynthetic CO2 bioconvertor based on green algae entrapped in low-sodium silica gels
Rooke, J. C.; Léonard, Alexandre ULg; Sarmento, H. et al

in Journal of Materials Chemistry (2011), 21(4), 951-959

A photosynthetic bioreactor for CO2 assimilation has been designed using silica sol-gel immobilisation technologies with the chlorophyta Botryococcus braunii (Kützing) and Chlorella vulgaris (Beijerinck ... [more ▼]

A photosynthetic bioreactor for CO2 assimilation has been designed using silica sol-gel immobilisation technologies with the chlorophyta Botryococcus braunii (Kützing) and Chlorella vulgaris (Beijerinck). The living hybrid gels formed revealed a mesoporosity that enabled diffusion of nutrients and gases, promoting the light and dark photosynthetic reactions from within the bulk of the material. To determine the efficiency of the photosynthetic bioreactor in terms of CO 2 remediation, the activity and viability of the encapsulated cells have been monitored through oximetry, 14C assimilation, pulse amplitude modulation fluorimetry and confocal microscopy, revealing a long term productivity of living hybrid materials capable of photosynthetic processes for at least 80 days. Structural and textural properties of the gels were established through 29Si MAS-NMR and N2 physisorption respectively. © 2011 The Royal Society of Chemistry. [less ▲]

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See detailDirect nano-in-micropatterning of TiO2 thin layers and TiO2/Pt nanoelectrode arrays by deep X-ray lithography
Faustini, M.; Marmiroli, B.; Malfatti, L. et al

in Journal of Materials Chemistry (2011), 21

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See detailFrom polyester grafting onto POSS nanocage by ring-opening polymerization to high performance polyester/POSS nanocomposites
Goffin, Anne-Lise; Duquesne, Emmanuel; Raquez, Jean-Marie et al

in Journal of Materials Chemistry (2010), 20

Polyester-grafted polyhedral oligomeric silsesquioxane (POSS) nanohybrids selectively produced by ring-opening polymerization of epsilon-caprolactone and L,L-lactide (A.-L. Goffin, E. Duquesne, S. Moins ... [more ▼]

Polyester-grafted polyhedral oligomeric silsesquioxane (POSS) nanohybrids selectively produced by ring-opening polymerization of epsilon-caprolactone and L,L-lactide (A.-L. Goffin, E. Duquesne, S. Moins, M. Alexandre, Ph. Dubois, Eur. Polym. Journal, 2007, 43, 4103) were studied as ‘‘masterbatches’’ by melt-blending within their corresponding commercial polymeric matrices, i.e., poly(epsilon-caprolactone) (PCL) and poly(L,L-lactide) (PLA). For the sake of comparison, neat POSS nanoparticles were also dispersed in PCL and PLA. The objective was to prepare aliphatic polyester-based nanocomposites with enhanced crystallization behavior, and therefore, enhanced thermo-mechanical properties. Wide-angle X-ray scattering and transmission electron microscopy attested for the dispersion of individualized POSS nanoparticles in the resulting nanocomposite materials only when the polyester-grafted POSS nanohybrid was used as a masterbatch. The large impact of such finely dispersed (grafted) nanoparticles on the crystallization behavior for the corresponding polyester matrices was noticed, as evidenced by differential scanning calorimetry analysis. Indeed, well-dispersed POSS nanoparticles acted as efficient nucleating sites, significantly increasing the crystallinity degree of both PCL and PLA matrices. As a result, a positive impact on thermo-mechanical properties was highlighted by dynamic mechanical thermal analysis. [less ▲]

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See detailPreparation of fire-resistant poly(styrene-co-acrylonitrile) foams using supercritical CO2 technology
Urbanczyk, Laetitia ULg; Bourbigot, Serge; Calberg, Cédric ULg et al

in Journal of Materials Chemistry (2010), 20

This work deals with the preparation and characterization of fire-resistant poly(styrene coacrylonitrile) (SAN) foams containing (organo)clays and/or melamine polyphosphate (MPP) as fire retardants using ... [more ▼]

This work deals with the preparation and characterization of fire-resistant poly(styrene coacrylonitrile) (SAN) foams containing (organo)clays and/or melamine polyphosphate (MPP) as fire retardants using supercritical CO2 as the foaming agent. The additives dispersion was first characterized with X-ray and transmission electron microscopy (TEM) analyses. Their presence clearly affected the cellular morphology, as observed by scanning electron microscopy (SEM). Then, the peak of heat release rate (PHRR) and total heat evolved (THE) were determined with a cone calorimetry test, performed on each foamed sample as a function of the foam density. Incorporation of clay (3 and 5 wt%) in the exfoliated state into the SAN foam clearly led to a significant decrease of PHRR, while intercalated and aggregated clay had a lower effect. Similar results were obtained with 10 and 20 wt% of MPP. The best results were obtained when exfoliated clay and MPP were combined, with a PHRR drop as large as 75%, thanks to the synergistic action of both additives. The magnitude of PHRR drop, related to the fire resistance, was found to be in direct relationship with the cohesiveness of the protective carbonaceous layer formed at the sample surface during combustion. Clay and MPP, when added together, are thus believed to favour the formation of a highly cohesive protective layer able to act as an efficient shield against the flame, despite the fact that the sample is originally composed of ~90% of voids. [less ▲]

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See detailPrevention of bacterial biofilms by covalent immobilization of peptides onto plasma polymer functionalized substrates
Vreuls, Christelle ULg; Zocchi, Germaine ULg; Thierry, Benjamin et al

in Journal of Materials Chemistry (2010), 20

In this study, robust antibacterial coatings were created on stainless steel through the covalent grafting of antibacterial peptides onto an organic-polymeric interlayer deposited by RF-glow discharge ... [more ▼]

In this study, robust antibacterial coatings were created on stainless steel through the covalent grafting of antibacterial peptides onto an organic-polymeric interlayer deposited by RF-glow discharge plasma. X-Ray photoelectron spectroscopy was used to characterize and optimize the two steps of the coating process. The biocidal activity of these surfaces was demonstrated against both Gram+ and Gram- bacteria using ISO tests. 3 to 6 log10 reductions of both Gram+ and Gram- bacterial strains were obtained compared to uncoated stainless steel and depending on the particular antibacterial peptide immobilized. Importantly the antibacterial surfaces were resistant to several cleaning conditions. The latter is significant as the stability of such antibacterial surfaces in close to real life conditions is a major concern and leaching, de-lamination, rearrangement and ageing of the coating can lead to insufficient long term biofilm resistance of the surface. [less ▲]

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See detailModeling the morphology and mechanical behavior of shape memory polyurethanes based on solid-state NMR and synchrotron SAXS/WAXD
D'Hollander, Stijn; Gommes, Cédric ULg; Mens, Raoul et al

in Journal of Materials Chemistry (2010), 20

A combination of solid-state proton Wide-line Nuclear Magnetic Resonance (NMR) relaxometry and synchrotron Small-angle (SAXS) and Wide-angle (WAXD) X-ray scattering was used to elucidate the microphase ... [more ▼]

A combination of solid-state proton Wide-line Nuclear Magnetic Resonance (NMR) relaxometry and synchrotron Small-angle (SAXS) and Wide-angle (WAXD) X-ray scattering was used to elucidate the microphase morphology of shape memory thermoplastic multi-block polyurethanes based on poly(3-caprolactone), as switching segment and polyurethane based permanent or hard segments (HS). The polyurethanes are produced from the condensation of 1,4-butanediol (BDO) with hexamethylenediisocyanate (HDI). The morphology – induced by the hard-segment crystallization – converts from dispersed randomly placed hard-segment domains into progressively more periodic, but interconnected HS nanophases with increasing HS content. Irrespective of the actual morphology, the SAXS data could be described satisfactorily by using a clipped Gaussian random field (GRF) model. The NMR data demonstrate that the HS domain fraction corresponds to the chemical feed, pointing at a complete phase separation. The material mechanical behavior during repeated deformation cycles can be explained on morphological grounds and involves a spatially heterogeneous plastic deformation of the hard domains. [less ▲]

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See detailDesign of photochemical materials for carbohydrate production via the immobilisation of whole plant cells into a porous silica matrix
Meunier, C. F.; Rooke, J. C.; Léonard, Alexandre ULg et al

in Journal of Materials Chemistry (2010), 20(5), 929-936

Photochemical materials that act as bioreactors by exploiting the photosynthesis mechanism have been fabricated by entrapping whole plant cells within a porous silica matrix. The immobilisation step has ... [more ▼]

Photochemical materials that act as bioreactors by exploiting the photosynthesis mechanism have been fabricated by entrapping whole plant cells within a porous silica matrix. The immobilisation step has been achieved via the in situ co-polymerisation of an aqueous silica precursor and a biocompatible trifunctional silane directly around cells. The cells remain undivided whilst the photochemical activity of the cells is well preserved over time. The design of a photochemical material that can act like a leaf, converting water into O2 and produce valuable organic compounds from CO2 under light irradiation is described. In particular, the increased excretion of polysaccharides by this photochemical material has been highlighted. The organic compounds formed have been extracted and analysed. The success of this work could open the door to new exciting photochemical materials with long-term photosynthetic activity and stability and to new green chemical processes for the conversion of solar energy into chemical energy with a concomitant reduction in CO2. © 2010 The Royal Society of Chemistry. [less ▲]

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See detailAll-in-one strategy for the fabrication of antimicrobial biomimetic films on stainless steel
Charlot, Aurélia; Sciannamea, Valérie; Lenoir, Sandrine et al

in Journal of Materials Chemistry (2009), 19

Here we report on an all-in-one approach to prepare robust antimicrobial films on stainless steel. The strategy is based on the layer-by-layer deposition of polyelectrolytes. A polycationic copolymer ... [more ▼]

Here we report on an all-in-one approach to prepare robust antimicrobial films on stainless steel. The strategy is based on the layer-by-layer deposition of polyelectrolytes. A polycationic copolymer bearing 3,4-dihydroxyphenylalanine units (DOPA, a major component of natural adhesives) was synthesized and co-deposited with precursors of silver nanoparticles as the first layer. The presence of DOPA units ensures a strong anchoring on the stainless steel substrate, and the silver nanoparticles are sources of biocidal Ag+, providing stainless steel with antimicrobial activity. We show that multilayered films, obtained by alternating this nanoparticle-loaded polycationic copolymer with polystyrene sulfonate, a commercial polyanion, results in stainless steel with high antibacterial activity against Gram-negative E. coli bacteria. The polycationic layers are a reservoir of Ag+ that can be reactivated after depletion. The whole process of film formation, including the synthesis of the copolymer, is conducted in aqueous media under very mild conditions, which makes it very attractive for industrial scale-up and sustainable applications. [less ▲]

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See detailPoly(caprolactone)/clay masterbatches prepared in supercritical CO2 as efficient clay delamination promoters in poly(styrene-co-acrylonitrile)
Urbanczyk, Laetitia ULg; Calberg, Cédric ULg; Benali, Samira et al

in Journal of Materials Chemistry (2008), 18(39), 4623-4630

Poly(styrene-co-acrylonitrile) (SAN)/clay nanocomposites with a high degree of clay exfoliation were prepared upon melt blending of pre-exfoliated poly(-caprolactone) (PCL)/organoclay masterbatches in a ... [more ▼]

Poly(styrene-co-acrylonitrile) (SAN)/clay nanocomposites with a high degree of clay exfoliation were prepared upon melt blending of pre-exfoliated poly(-caprolactone) (PCL)/organoclay masterbatches in a Brabender-type internal mixer. These highly filled masterbatches were synthesized by a one-pot process using supercritical carbon dioxide as a polymerization medium. During their dispersion into SAN, PCL is expected to act as a compatibilizer at the polymer–clay interface as it is miscible with the host matrix under these conditions. Reference nanocomposites based on direct melt mixing of the commercial organoclay were also prepared for the sake of comparison. The superiority of the masterbatch route in term of clay delamination efficiency has been evidenced by XRD analysis, visual and TEM observations. The effect of the nanocomposite morphology on the polymer properties was then investigated. A substantial improvement of the fire behaviour and a decrease in gas permeability have been observed for the nanocomposite containing the highest level of clay exfoliation, accompanied with a higher brittleness as evidenced by traction and impact tests. [less ▲]

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See detailMagnetic nanoparticles coated by temperature responsive copolymers for hyperthermia
Aqil, Abdelhafid ULg; Vasseur, Sébastien; Duguet, Etienne et al

in Journal of Materials Chemistry (2008), 18(28), 3352-3360

Various temperature-responsive N-isopropylacrylamide-based functional copolymers were prepared and used for the stabilization of iron oxide nanoparticles. The copolymers investigated are poly(acrylic acid ... [more ▼]

Various temperature-responsive N-isopropylacrylamide-based functional copolymers were prepared and used for the stabilization of iron oxide nanoparticles. The copolymers investigated are poly(acrylic acid)-b-poly(N-isopropylacrylamide) (PAA-PNIPAM) and poly(acrylic acid)-b-poly(N-isopropylacrylamide)-b-poly(acrylate methoxy poly(ethylene oxide)) (PAA-PNIPAM-PAMPEO), with different molecular weights. The coated nanoparticles were characterized in terms of size by a combination of dynamic light scattering (DLS) and transmission electron microscopy (TEM). A sharp temperature transition was confirmed by particle size measurements vs. temperature. In addition, the stealthiness of the coated nanoparticles has been assessed in vitro by the haemolytic CH50 test. These measurements evidenced the crucial role of the PEO segments on the stealthiness of the nanoparticles and thus that such copolymers are particularly suitable for biomedical applications. Preliminary experiments of alternating magnetic field induced heating were performed and specific absorption rates of the various samples were recorded. [less ▲]

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See detailFoams of polycaprolactone/MWNT nanocomposites for efficient EMI reduction
Thomassin, Jean-Michel ULg; Pagnoulle, Christophe; Bednarz, Lukasz et al

in Journal of Materials Chemistry (2008), 18(7), 792-796

Nanocomposites of polycaprolactone (PCL) filled with multi-walled carbon nanotubes (MWNTs) were foamed by supercritical CO2 in order to prepare materials with reduced electromagnetic interference (EMI ... [more ▼]

Nanocomposites of polycaprolactone (PCL) filled with multi-walled carbon nanotubes (MWNTs) were foamed by supercritical CO2 in order to prepare materials with reduced electromagnetic interference (EMI). Two mixing techniques were used, i.e., melt blending and co-precipitation. Shielding efficiency as high as 60 to 80 dB together with a low reflectivity was observed at a very low vol% of MWNTs (0.25 vol%). The reflectivity of the nanocomposites was advantageously decreased upon foaming. The uniformity of the open-cell structure was assessed by scanning electron microscopy. These foamed PCL/MWNT nanocomposites are very promising EMI shielding materials because their performances result from absorption at low filler content and not from reflection at relatively high filler content as was previously the case. [less ▲]

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See detailPhotosynthesis within porous silica gel: Viability and activity of encapsulated cyanobacteria
Rooke, J. C.; Léonard, Alexandre ULg; Sarmento, H. et al

in Journal of Materials Chemistry (2008), 18(24), 2833-2841

In the framework of designing novel bioreactors, the encapsulation of photosynthetic cyanobacterial strains of the genus Synechococcus, PCC 6301, PCC 7002 and Cyanothece PCC 7418, within mesoporous silica ... [more ▼]

In the framework of designing novel bioreactors, the encapsulation of photosynthetic cyanobacterial strains of the genus Synechococcus, PCC 6301, PCC 7002 and Cyanothece PCC 7418, within mesoporous silica networks has been achieved via the acidification of aqueous colloidal silica precursors at ambient temperature. The effect of the silica matrix on the external membrane of the cells has been studied. The viability of the cells over a three month duration has been assessed using transmission electron microscopy, epifluorescence microscopy, UV-visible spectroscopy and high-performance liquid chromatography. The bioactivity of the encapsulated cyanobacteria was detected via the assimilation of NaH14CO3. Although most cells entrapped within the silica gel remain undivided, some cells continued to divide even when there was limited space. TEM studies have revealed an interaction between the silica gel and the cell membrane. HPLC studies highlight that the photoactive pigments in PCC 6301 and PCC 7002 can be preserved for up to 12 weeks whilst PCC 7418 lost its photosynthetic pigments after two weeks post-immobilisation. These results suggest that certain strains of cyanobacteria are able to photosynthesise within a hybrid gel yielding the possibility of novel photobioreactors. © The Royal Society of Chemistry 2008. [less ▲]

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